Efficient Removal of Dead Attachments and Links in a Large Forum

[Xeite]

I run a large forum with 35,000 users and have approximately 40GB of attachments from old posts that are no longer being visited. I decided to manually delete these attachments through the admin menu, it involved a lot of clicking since there were about 1,200 pages with 25 attachments on each page. After hours of manual clicking and removing old attachments, I managed to complete the task. Unfortunately, I encountered a problem where the posts still contained links to these attachments, which were no longer functional. This included both image thumbnails and actual attachments in formats such as ZIP files, but all of them were dead and inactive.

Is there a simple way to remove these dead links to the deleted attachments?

[opentype]

Normally, you would delete the topics themselves and then the orphaned attachments would be cleaned up later through background tasks. 

If you just remove the files, then sure, the links to those files will remain.